Look Back
by BunniesOfDoom
Summary: Okabe switches minds with his ten-year-old self. Confusion ensues. Post-movie.
1. Chapter 1

**Inspired by The Variable by megannn.**

* * *

It starts innocently enough. Kurisu is in the lab with Okabe, Daru, and Mayuri. She and Okabe are arguing ("flirting" according to Daru) about his latest idea for an experiment, Mayuri is working on a cosplay, and Daru is doing something perverted on the computer. It's been two weeks since the incident with the R world line, and she's assumed that things have gone back to normal.

"So the next phase of this experiment should be—" Okabe breaks off in midsentence, gazing around the lab like he's never seen it before.

Kurisu breaks the silence after a moment. "Okabe? Something wrong?"

Okabe whips his head around to stare at her. Mayuri, who seems noticeably worried now, chimes in. "Okarin? What's going on?"

Okabe quickly shifts his focus to her. "Mayuri?" he murmurs. He sounds confused. Finally, he looks around again and asks, in a tentative voice, "Where am I?"

Daru sighs and rolls his eyes. "Seriously? You're trying to pretend you don't know where we are? Lamest prank ever, dude."

Kurisu is getting annoyed too. "Is this just an attempt to get out of admitting that you were wrong?" she huffs, crossing her arms. "I'll admit, your acting skills are impressive, but you can't honestly expect me to believe—"

Looking panicked now, Okabe cuts her off, gesturing to her and Daru. "Look, I don't know who either of you are, but—" This time, Daru cuts him off.

"So now you're pretending that you don't know either of us too. Seriously, Okabe, you need to work on your sense of humor."

Mayuri, meanwhile, has been ignoring their discussion, and is studying Okabe with a frown on her face. "Okarin?" she finally ventures. He turns back towards her, looking lost and confused. "You really don't remember anything? Not Kurisu, or Daru, or the Future Gadget Lab?"

''That's what I've been trying to tell you," Okabe sighs, relieved that somebody seems to be listening to him.

"You can't really believe this, can you?" Kurisu asks, incredulous.

"He's not lying," Mayuri says, with no trace of doubt in her voice. "Okarin, I need you to tell me what's wrong—what's going on?"

Perhaps most surprisingly, Okabe does just that.


	2. Chapter 2

Kurisu thinks that this is officially the strangest situation she's ever been in. Mayuri had taken Okabe aside, chatted with him for a couple minutes, and then gathered her and Daru to explain what was going on. "What do you mean he's ten years old!" she burst out, looking at Mayuri incredulously.

Mayuri shushed her almost impatiently, and responded, more quietly, "He only remembers stuff from when he was ten."

"So he has his ten-year-old mind in his present-day body?" Daru asked. "This still sounds like a really bad prank."

Mayuri crossed her arms. "It's not a prank, and he's not lying. I can tell." She thought for a moment, before asking the question that was on everyone's minds. "What are we going to do?"

Kurisu, still in disbelief about the situation, finally spoke again. "Well, you said that you're sure he's not making this up. So, if he's currently a ten-year-old trapped in a twenty-year-old's body, then we should probably figure out how this happened, and how to fix it." She doesn't understand how Mayuri can be so sure, but since she's their resident Okabe expert, she decides to just go with it.

"How could something like this happen?" queried Daru, looking puzzled.

Kurisu bit her lip and ran her fingers through her hair, thinking. Finally, she voiced her thoughts. "Maybe it's an after effect of his time travel experiences? I honestly have no idea. And I know even less about how to fix something like this. I'll try to think of a solution. While I do that, we should probably keep him here." Another thought occurs to her. "And we should probably try to avoid telling him too much about the future. Who knows what kind of consequences that could have."

"You mean we have to keep Okarin in the dark about all this?" Mayuri asked, upset. "That's not a very nice thing to do."

"I'm sorry, but I think it's for the best that he doesn't know everything about his future yet." Kurisu responded, hoping to placate Mayuri.

"Fine," Mayuri acquiesced, but she didn't sound very happy about it. "I'll keep Okarin busy while you two figure this out." She stood up and walked over to Okabe, who was sitting on the couch where Mayuri had left him, staring around the lab in confusion.

"This is going to be fun," said Daru sarcastically. "Where do we even begin?"

* * *

Kurisu and Daru take up residence at the whiteboard next to the couch, attempting to brainstorm a solution to their very unusual problem. While they work, they can hear Okabe and Mayuri's quiet conversation.

"When did I get so tall?" Okabe asks Mayuri. His voice is quiet, almost as if he's afraid of it.

Mayuri giggles. "Isn't it amazing?" she grins. "I mean, you were always taller than me, but once you turned sixteen you just kept growing!"

Okabe laughs with her, then goes quiet for a minute. After a minute, he asks, "Who are those two?" He gestures to Kurisu and Daru.

"Oh, right, I forgot to introduce you! That's Hashida Itaru," she explains, gesturing to Daru. "Or Daru, which is what you and I call him." She points to Kurisu. "And that's Makise Kurisu. They're our friends!"

Okabe stares at Daru and Kurisu for a moment before replying. "They're our… We have friends?" he asked, sounding absolutely astonished.

"Yep!" Mayuri chirped excitedly. "Mayushii is so happy! You don't have to be so lonely anymore!"

Okabe considers that for a moment. "Mayuri, I'm never that lonely. After all, I have you."

Mayuri seems to freeze for a moment. Finally, she responds in a very small voice, "Thank you, Okarin."

* * *

Later that evening, after Mayuri makes dinner and Okabe has fallen asleep on the couch (apparently having your mind jump forward ten years is exhausting), they gather around the microwave to discuss a plan of action, keeping their voices low.

"Well, Daru and I have pretty much worked out that it must be an after effect of the time travel," Kurisu begins. "If he could disappear from this worldline, then it seems reasonable that something like this could happen. Unfortunately, we still have no idea how we're supposed to fix this or undo it."

"On another note," Daru interrupts the conversation. "What's going on with Okabe? Why is he so quiet?"

"It could be because of trauma from the mind switch," Kurisu hypothesizes. "He could be in shock."

"There's nothing wrong with Okarin," announces Mayuri.

"How can you be so sure?" Kurisu ponders the possible consequences of time travel and switching minds with one's younger self. "Who knows what time traveling could have done to him?"

"He's not acting strange," corrected Mayuri. "He's acting perfectly normal."

"But he's so quiet, and hesitant, and he hasn't done an evil laugh even once," argued Daru. "That's not normal for him."

"He's ten years old. This is how he acted when he was ten," Mayuri points out. "Okarin will be fine," she assures them.

"I've got to go home," says Daru, now that the issue is resolved. "May, you should probably head home too."

But Mayuri just shakes her head. "I can't go home. Who's going to stay with Okarin if I leave? I'm going to stay here. I already told my parents."

"But Mayuri, you don't have any of your stuff here," Kurisu points out.

"That's not a problem! Mayushii keeps some clothes and other stuff here in case of emergencies," she explains. "So there's no issue in me staying here."

"I'm going to stay here as well," Kurisu decides. "I'll need to run over to my hotel to grab my clothes, though. We'll try to figure out how to return Okabe to normal tomorrow," She finishes, glancing over at the sleeping figure on the couch.


	3. Chapter 3

**The stuff about the amygdala that I mention is all true.**

* * *

Kurisu takes a long time to fall asleep that night. Her thoughts are occupied by Okabe: why on earth the younger version of him is so shy and quiet, and brainstorming a way to fix the situation. She still remembers how to build the time leap machine, and asking Daru to hack SERN again is an easy task. But what would the time leap machine accomplish? Its range isn't far enough to send Okabe back in time ten years, and even if it could, there's no way to return older Okabe to the present. Not to mention, Kurisu remembers sadly, Okabe wouldn't want her to build it. He had been so angry when she built it before. No, not angry—scared.

The version of Okabe she'd met when she had traveled back in time had been quiet as well, and she wonders if the loud, obnoxious personality she's accustomed to is just part of his mad scientist persona. Another possibility occurs to her. Okabe had adopted his mad scientist persona as a way to assure Mayuri that she was still needed. The ostentatious loudness could be meant to reassure Mayuri as well, to remind her that even with her grandmother gone, she still had people that cared about her. It would certainly explain the drastic differences between his older self and his younger self.

* * *

Fortunately, whatever had happened to Okabe had occurred on a Friday afternoon, so they were all able to stay at the lab and attempt to find a solution. They fall into a routine; Mayuri entertains Okabe and keeps him occupied with easy conversation and TV, while Kurisu and Daru brainstorm, helping out occasionally, and eavesdrop on their conversations. Kurisu has decided that Mayuri must be some kind of miracle worker, because he hasn't asked to leave the lab or to see his parents once.

The somewhat comfortable routine they've fallen into is disrupted Sunday evening. Daru announces that he won't be able to return to the lab until the next afternoon, because he has to go to class. This isn't too much of a problem, and anyway, Daru can help by telling Okabe's professors that he's sick, since Okabe obviously won't be attending his classes.

She's forgotten about Mayuri, though. At first, Mayuri is determined to stay with her friend, but Kurisu manages to convince her to go to school, reminding her that she can come over to the lab as soon as classes are over. "Besides," Kurisu continues. "I don't have any lectures tomorrow, so I can stay here with Okabe."

Mayuri looks dubious at her suggestion, but eventually is convinced enough to start heading home. Kurisu can't blame her, she's trying to sound more confident than she actually is. She's not very good with children on a good day, let alone with a ten-year-old version of one of her friends. She's determined to help though, and that has to count for something.

* * *

Monday morning is awkward. Kurisu manages to keep Okabe occupied with the TV, but the silence in the room is heavy, and she doesn't know what to do. Okabe finally breaks the silence when she's in the middle of going over her notes for the lecture she's giving on Wednesday. "What's that?" he asks, pointing to a structure on one of her diagrams of the brain. Apparently he's been reading over her shoulder.

Kurisu is surprised by his interest. "That's the amygdala," she explains, and his eyes light up with interest. "It's involved in strong emotions, especially fear." He nods, and they quickly fall into a routine; he asks questions, she answers and explains. It's good practice for when she actually gives the lecture, and it's keeping him occupied.

She can't help but notice how, at ten, he's very perceptive and learns quickly, even though the topics she's discussing with him are confusing for even the top college students in her classes. She begins to wonder if there's some reality to his claims that he's a genius; if he's this smart at ten, then who knows how smart he could be in ten years.

* * *

The day goes by quickly once Okabe expresses an interest in her favorite subject, and when Mayuri comes running in after school, she finds them sitting comfortably together on the couch, still going over the lecture notes, Okabe peppering Kurisu with endless questions.

They finally break up the discussion when Daru returns, so they can decide on a plan of action for the rest of the week. Kurisu has just turned around when Okabe starts suddenly, and gasps, just like he did before. He starts gazing around at the lab again, this time in relief.

"Okarin?" Mayuri presses him. "Something wrong?"

There's a moment of silence, then Okabe responds, "Nothing's wrong, sweetheart. In fact, I'd say that everything is as it should be."

"You're back!" Mayuri squeals, and proceeds to tackle him in a hug. Daru and Kurisu both sag with relief.

"I hope I wasn't too much trouble?" Okabe asks, returning Mayuri's embrace.

So he remembers what happened. Daru goes to make a sarcastic comment, but Kurisu elbows him in the ribs and responds, "No trouble at all. We had it covered." Mayuri is speaking rapidly, telling him everything that happened during the mind switch. Kurisu smiles, lost in thought. This incident has given her a lot to think about. Regardless of the consequences of Okabe's swap, she's glad to have him back.

* * *

 **The End?**

 **Probably, although I may write an epilogue at some point.**


	4. Epilogue

**Finally thought of an** **epilogue for this story! And yay for completing my first multi-chapter story!**

* * *

Of course, Kurisu doesn't get a chance to talk to Okabe alone until much later. Mayuri had been ecstatic to have her friend back to normal and had talked nonstop with him for hours, until she finally fell asleep on the couch. Mostly she'd been asking him questions about what had happened where (or more appropriately when) he was and explaining what had happened with ten-year-old him. Kurisu is about to head home when she hears Okabe's heavy footsteps behind her. She turns around to face him, shoving a few more papers in her bag as she stands near the doorway.

"I'm hoping that I wasn't too much trouble while I was—gone," he says sheepishly, not quite meeting her eyes.

"You weren't," she tries for a casual tone, trying to reassure him. Judging by the look on his face, it's not working.

He still won't look her in the face. "I didn't say anything too—" he cuts himself off, suddenly fascinated by the floor.

Kurisu sighs internally. So he's back to hiding any problems that he has from her. At least his ten-year-old self had been honest and upfront with them.

"Embarrassing?" she finishes for him, and he shoots her a grateful look. "Not really," she replies, thinking. "Although you seemed afraid of your voice and were astonished that you grew so tall," she says, smirking. "And you were incredibly surprised when you found out that you had friends," she finishes the list. "Would that really be so surprising for your younger self?" Before he can come up with more excuses or denials, she adds, "I'm just trying to help, you know."

He pauses for a moment, thoughtful. Finally, he decides to be honest with her. "Actually, yeah, that would be surprising to my younger self." He quickly adds, "That _I_ would have friends, not Mayuri. In fact, if Mayuri hadn't insisted on hanging around me so much when we were younger, I always felt that she'd have had lots of friends." He shakes his head tiredly.

"It's not your fault, you know," she murmurs. "And for what it's worth, I don't think Mayuri minds." Hopefully, this is enough to put him at ease.

He does seem a little more peaceful now, and the worried frown is fading from her face. "I should probably head home now," she calls over her shoulder, turning to head out the door. As she walks out, she whispers, "I missed you." Behind her, Okabe's mouth curves into a smile.

Walking home, she ponders the questions she didn't ask. Someday she'll ask him about how quiet his ten-year-old self was, and laugh with him about the fact that they'd bonded over science. They'll discuss the possible causes and consequences of his mind-swapping adventure. But those are questions for another day. For now, the important thing is that he's back and he's doing okay. Everything else they can handle together.


End file.
